Rotella T6 15w40 ?? Best oil for CAT ?

Cat is recommending 10W30.......I wouldn’t sweat it , use what your comfortable with . Cold starts is the protection your giving up .

Ive been on T6 5W for years and like it....

 

Chances are he’s got a tired engine that’s already leaking some thru the pistol seals. Doesn’t want to constantly add oil since most of the burn is happening while the oil is thin. I can only guess I had an old junker car where I needed to put 15w-50 so the SOB wouldn’t need oil every month.

 

Thanks for the post and reply.
Yeah T6 is a very good oil, I was just curious as to your reason to go thicker oil when cold than the T6 5w-40 syn.

When the oil is "thin" are you referring to when it's cold and the oil is 5W vs 15W?

Usually oil burn isn't at startup or warmup though, it's at operating temp(hot)

0W-40 syn, 5W-40 syn, 15W-40 syn or dino are all the same 40 Viscosity oils when hot.

 

I have used rotella in whatever it was pretty much my entire life where possible in trucking. Many engines really did not need much. If you wanted to know if your engine would go through a bit of oil, look under it. If it has sit long enough it will mark the ground or pavement underneath of it.

I understand they are making some for gasoline engines now. On the next change I would be giving these a try. I'll have to replace or fill most all of the fluids on the personal vehicle anyhow. The recent drive I took with it revealed a certain amount of need for it from the behavior of the truck. I don't drive it very much. Maybe 200 miles a year if that.

One other thing, I recall from trucking the possibility of the pan below the engine being a plastic or some other material that is not metal. I have learned to be more diligent in checking oil on these because sometimes the bolt that sits where you drain it will eat into the threads a bit much and leak a bit.

With older cars late 60's and early 70's Ive had good luck with oil in those engines. However some of the 90's vehicle V6's had to go into a shop to tear the engine all the way into the crankcase to get at certain seals that have gone bad and go through oil. One engine actually failed it's mains the flat surfaced bearings holding the crankshaft after it viberated through enough of them to finally lose it's place and physically kill the engine. That one was a head scratcher.